Gut microbes modulate immune pathways in intestinal stem cells to influence their lineage

肠道微生物调节肠道干细胞的免疫途径以影响其谱系

• 批准号: 10409676
• 负责人: Nicolas Buchon
• 金额: $ 57.7万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-12 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10409676
• 关键词: Address; Affect; Animal Model; Bacteria; Biological Models; Cell Differentiation process; Cell Lineage; Cells; Characteristics; Development; Disease; Disease Progression; Drosophila genus; Drosophila melanogaster; Enterocytes; Environment; Epithelial; Equilibrium; Etiology; Exposure to; Face; Feedback; Food; Future; Gastrointestinal tract structure; Genes; Genetic; Genetic Models; Goals; Health; Homologous Gene; Immune; Immune response; Immune signaling; Indigenous; Infection; Inflammatory; Ingestion; Intestinal Diseases; Intestines; Janus kinase; Mediating; Microbe; Molecular; Mus; Oral; Outcomes Research; Pathogenicity; Pathology; Pathway interactions; Pattern; Peptide Initiation Factors; Physiology; Play; Process; Role; Shapes; Signal Pathway; Signal Transduction; Structure; Testing; Tissues; Transducers; Virulence; Work; Xenobiotics; base; cell behavior; cell type; epidemiology study; gastrointestinal epithelium; gene network; gut homeostasis; gut microbes; gut microbiota; immunogenicity; improved; insight; intestinal epithelium; intestinal homeostasis; knock-down; microbial; microbial host; microbiome; microbiota; novel therapeutics; pathogen; pathogenic microbe; progenitor; response; stem cell differentiation; stem cell fate; stem cell proliferation; stem cells; transcriptomics; translational study

An increasing number of epidemiological studies suggest that intestinal microbes are not only central to maintaining host health, but also constitute etiological factors for the initiation and progression of diseases of the intestinal tract. However, the mechanisms by which microbes affect intestinal health remain largely unknown. Using a powerful genetic model organism, Drosophila melanogaster, we have recently shown that microbes not only alter intestinal stem cell (ISC) proliferation, but also modulate the relative proportions of differentiated cell types in the epithelium. Importantly, we found that pathogens promote an enteroendocrine (EE) fate while non- pathogenic microbes promote an enterocyte (EC) fate, suggesting that pathogenic and non-pathogenic microbes influence ISC lineage in an opposing manner. Based on these results, and from our previous studies, we hypothesize that gut microbes modulate immune signaling pathways in ISCs to influence their lineage decisions. To test this hypothesis, we propose the following specific aims: Aim 1: We will determine the microbial characteristics (immunogenicity, virulence/damage) that modulate the cellular composition of the gut epithelium in both Drosophila and murine enteroids. In parallel, we will determine the relative contributions of cell loss, ISC proliferation and differentiation to this process. Aim 2: We will characterize how a classical immune pathway, the Imd/Relish pathway (NFκB homologue), acts in Drosophila ISCs and murine enteroids to influence differentiation in response to gut microbes. We will first identify ISC-specific Relish target genes using a combination of cell type-specific transcriptomics and targeted DamID (TaDa). We will then analyze how the Imd/Relish pathway interacts with other gene networks known to control ISC differentiation. Our studies will therefore demonstrate a new role for Imd/Relish that goes beyond the control of immune effectors and provide mechanistic insight into how this pathway alters stem cell lineage and epithelial composition. Aim 3: We will investigate how activation of the Janus kinase (JAK)-signal transducer of activator (STAT) pathway triggers EE fate commitment in Drosophila ISCs and murine enteroids. We will identify direct and indirect target genes of STAT in order to characterize downstream mechanisms and delineate the impact that JAK-STAT signaling has on ISC differentiation. Finally, we aim to clarify how the interaction between the JAK-STAT and Imd/Relish pathways determines the opposite ISC fates produced in the gut by pathogenic and non-pathogenic microbes. Outcomes of this research will improve our understanding of how the microbiota alters intestinal homeostasis in health and disease and demonstrate that different gut microbes (pathogenic vs non-pathogenic) alter gut epithelial composition by differentially modulating ISC differentiation. We will also identify a new role for pathways classically defined as immune pathways in affecting ISC differentiation, providing new mechanistic insight into how ISCs respond to their microbial environment. The mechanistic principles identified in our study will therefore pave the way to a better understanding of diseases of gut origin and potentiate the development of new therapies.

越来越多的流行病学研究表明，肠道微生物不仅是 维持宿主健康，但也构成了疾病的主动性和发展的病因因素 肠道。但是，微生物影响肠道健康的机制仍然很大程度上未知。 使用强大的遗传模型有机体果蝇Melanogaster，我们最近表明微生物不是 仅改变肠道干细胞（ISC）增殖，但也调节分化细胞的相对比例 上皮中的类型。重要的是，我们发现病原体会促进肠内分泌（EE）命运，而非 - 致病微生物促进肠上皮细胞（EC）命运，表明致病性和非病原性微生物 影响ISC血统以相反的方式。基于这些结果以及以前的研究，我们 假设肠道微生物调节ISC中的免疫信号通路以影响其血统 决定。为了检验这一假设，我们提出以下特定目的：目标1：我们将确定 微生物特征（免疫原性，病毒/损害）调节肠道的细胞组成 果蝇和鼠肠内的上皮。同时，我们将确定细胞的相对贡献 损失，ISC增殖和与此过程的分化。目标2：我们将表征经典的免疫 途径是IMD/RESIS途径（NFκB同源物），作用于果蝇ISC和鼠肠内影响 响应肠道微生物的分化。我们将首先使用A 细胞类型特异性转录组学和靶向DAMID（TADA）的组合。然后，我们将分析如何 IMD/RESIS途径与已知控制ISC分化的其他基因网络相互作用。我们的研究将 因此，展示了IMD/Relish的新作用，超出了免疫效应的控制并提供 关于该途径如何改变干细胞谱系和上皮组成的机械洞察力。目标3：我们将 调查激活激活因子（STAT）途径的激活如何激活EE 果蝇ISC和鼠肠内的命运承诺。我们将确定的直接和间接目标基因 统计目的是表征下游机制并描述Jak-STAT信号的影响 在ISC差异上。最后，我们旨在澄清jak-stat和imd/felish之间的相互作用 途径决定了通过致病性和非致病微生物在肠道中产生的相反的ISC命运。 这项研究的结果将提高我们对微生物群如何改变肠内稳态的理解 健康和疾病，并证明不同的肠道微生物（致病性与非致病性）改变了肠道 通过不同调节ISC分化的上皮组成。我们还将确定途径的新角色 经典定义为影响ISC差异化的免疫学，提供了新的机械洞察力 ISC如何应对其微生物环境。因此，我们研究中确定的机械原理将 为更好地理解肠道疾病的理解和新疗法的发展铺平道路。